1. Field of the Invention
The invention relates to a weighted absolute difference based deinterlace method and apparatus.
2. Description of the Related Art
The National Television Standards Committee (NTSC) is responsible for setting television video standards in the United States. The NTSC standard is interlaced. Each frame (480 viewable lines) is broken into two sections called fields (240 alternating viewable lines). A field containing even lines (0, 2, 4, . . . ) is termed an even field. Similarly, a field containing odd lines (1, 3, 5, . . . ) is termed an odd field.
Every 1/60 second, the NTSC standard requires displaying an even or an odd field. Because this process is happening quickly, the eye is tricked into seeing a full frame picture. The image quality resulting from the NTSC standard is acceptable on smaller television sets—those having roughly 27 inches viewable area. The image quality, however, quickly degrades as the screen size increases. This is because the NTSC standard creates artifacts, e.g., flickering, shimmering, and diagonal line jaggedness, visible to the eye on large screens. This image quality degradation renders the NTSC standard also unacceptable for high definition television (HDTV). And NTSC is incompatible with most personal computer and liquid crystal (LC) displays that operate on progressive scan. Progressive scan presents a higher quality alternative to the interlaced NTSC standard. Progressive scan require displaying alternating odd and even lines with each frame.
Accordingly, a need remains for an improved method and apparatus that converts interlaced to progressive scan signals.